Molds for confectionery products are one of the most important parts of the confectionery production process. Molds determine the design of the product, including its final visual quality, as they are the carrier of the confectionery product from the first deposit of a liquid confectionery mass until the final confectionery product reaches the packaging area. During this process the mold/product system is typically cooled down or heated up several times by passing it through a processing unit which is divided into zones having different temperatures, the different temperatures being attained using a series of cooling/heating units.
The heat transfer rate between the mold/product system and the cooling/heating air is of fundamental importance to the energy consumption of the processing unit and the final quality of the confectionery product.
Conventional molds are generally designed as having a top surface which contains specific cavities for the liquid confectionery mass, sides which comprise the outer rim and a bottom surface which has various numbers of lengthwise and crosswise bars for achieving sufficient rigidity and stability (less bending).
Conventional molds mostly consist of poly-carbonate (e.g. Makrolon, Lexan or Tarflon). Makrolon represents generally the preferred material. Said polycarbonates are food grade, rigid and enable a surface roughness small enough to achieve a glossy chocolate surface.
However, such mold designs are not optimal regarding the fluid dynamic properties, since dead zones and uncontrolled stationary vortices are generated which inhibit heat transfer (see FIG. 1). In general, fluid-dynamic and energetic aspects of the mold as carrier of the confectionery product are not considered on an industrial scale. Accordingly, the cooling and heating cabinets and their process capabilities are adapted regardless of the high level of energy consumption.
A further disadvantage of conventional molds for the production of confectionery products is that it is difficult to realize a homogenous cooling/heating of the confectionery mass and thus, a homogenous solidifying during the production process, since the molds have different wall thicknesses according to the employed shape the cavities.
In general, molds have hitherto been thought of as merely carriers for the confectionery product mass; they have not been considered as forming part of the production process.
EP 0 429 969 B1 describes a chocolate mold formed of plastic material having circular openings in the frame which guide the cooling air stream through the underside of the chocolate mold. The specific design of said chocolate mold enables an accelerated, more homogenous cooling/heating of the chocolate mass during the production process.
The development of a computational model which can predict the cooling behavior of chocolate in a simple chocolate mold during the commercial manufacture is described in the article “Modelling temperature distributions in cooling chocolate moulds” by P. J. Fryer et al. However, no detailed design of chocolate molds having improved cooling/heating characteristics is mentioned.